Grant Likely schrieb: > On Tue, Aug 31, 2010 at 10:16 AM, Vasiliy Kulikov <segooon@xxxxxxxxx> wrote: >> On Tue, Aug 31, 2010 at 18:08 +0200, Julia Lawall wrote: >>> On Tue, 31 Aug 2010, walter harms wrote: >>>>> if (strncmp(model, "PowerBook", strlen("PowerBook")) != 0 && >>>>> strncmp(model, "iBook", strlen("iBook")) != 0 && >>>>> strcmp(model, "PowerMac7,2") != 0 && >>>>> >>>> is there any rule that says when to use strncmp ? it seems perfecly valid to use strcpy here >>>> (what is done in the last cmp). >>> Perhaps there are some characters after eg PowerBook that one doesn't want >>> to compare with? >> It seems to me that model has no '\0' in the end. If model is got from >> the hardware then we should double check it - maybe harware is buggy. >> Otherwise we'll overflow model. > > Model does have \0 at the end. This code is using strncmp to > purposefully ignore the model suffix. > >> But why strcmp(model, "PowerMac7,2")? IMO it should be replaced >> with strncmp(). > > We use strcmp when parsing the device tree because the the length of > the model property string is unknown and in most cases we *must* match > the exact entire string, such as with this PowerMac7,2 example. Using > strncmp would also happen to match with something like > "PowerMac7,2345" which is not the desired behaviour. > hi Grant, whould you mind to use you explanation as comment in the code ? Tthat the strncpy/strcpy difference is important should be noted. that would be clearly a bonos with further audits. re, wh -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html